Michael Simmelsgaard, head of offshore business at Swedish utility Vattenfall, said the industry would cross the 10 MW turbine threshold "faster than many expect now", without being more specific. A 10 W turbine could power about 9,000 homes. "We will definitely see these big turbines," he added.

DONG Energy's wind business, Samuel Leupold, laid out more ambitious plans: "We believe we can utilize (turbines) in the range of 13 to 15 megawatts," he said on the sidelines of an offshore wind conference in London this month - the first time an industry executive has given such a high figure. Previously, companies have only spoken about turbines in the region of 10W.

EnBW also said it was turning to megaturbines. "Size is an important driver of efficiency," said Dirk Guesewell, its head of generation portfolio development. "Bigger rotors mean fewer turbines and foundations are needed to achieve the same capacity."

German turbine maker Senvion said it was developing megaturbines of over 10 MW. While the machines are still in the design stage, it said it was already offering them for future use to wind farm operators.